Leaking Information

Tuesday earlier this week, I gave a presentation on the topic of Comparing Information Without Leaking It.  This is a class of problems in which two parties are interested in ensuring they both know some secret so they can then safely talk about it.  Wouter Teepe wrote his Ph.D. Thesis on an extension of this problem, and has a number of excellent ideas as to where, potentially, algorithms which solve this class of problems might be used.  A particularly memorable one concerned the recent EU - USA spate about air passenger data.  The EU wants to avoid leaking it, and the US wants to compare it to their terror lists.  Well, that's just an instance of Comparing Information Without Leaking It, so using existing algorithms that can be achieved - technically.  I'm not holding my breath on the politics however, especially, as I suspect, the US is actually just as interested in data mining this information (and using it for a variety of not entirely noble causes), as it is in identifying known suspects.  Of course, data mining isn't a perfect science for finding terrorists...

In any case, I've been casually considering various other information leaks as a result.  Here's an irritating one I can't fix easily:  PicasaWeb uses your Google username as an element of your web album URL.  For example, a recently uploaded Panorama is at http://picasaweb.google.com/eamon.nerbonne/Panoramas.  I can't easily change that URL (and certainly not after posting links to it everywhere), and the only options you can change it too are other google usernames you have.  Well, that's great, but those also coincide with your gmail google address.  In conclusion, I'm looking forward to more spam promptly; because it's trivial to harvest picasaweb of valid gmail addresses now.